This invention applies a novel lever coupling to a spring loaded brake. The clutch is engaged by pulling levers inward and disengaged by the release of the inward pressure on the levers. Forward or reverse progression of the wheelchair is affected by the corresponding forward or reverse displacement of levers.
The invention can incorporate the use of various types of clutches such as drum-type clutch with external shoes, a drum-type clutch with internal expanding shoes, single and multi-disk clutches and hydraulic actuators.
In a preferred embodiment, a friction clutch is used for all three functions, forward, reverse and braking. The object of this invention is to provide a lever propelled with a chair comparable maneuverability to wheelchairs driven by hand rims.
U.S. Pat. No. 4,506,900 shows a lever operating wheelchair with a differential link mechanism connected to a single operational lever. This invention also includes forward and backward clutch mechanism. This patent does not appear capable of the maneuverability disclosed in the Brubaker/McLaurin invention.
U.S. Pat. No. 3,666,292 discloses a lever propelled wheelchair with a swingable chassis.
U.S. Pat. No. 3,897,857 discloses a spring activated brakedrum for a wheelchair hub.
The following references are less pertinent than those listed above: U.S. Pat. Nos.
4,455,029 PA1 4,506,901 PA1 4,471,972 PA1 4,354,691 PA1 3,953,054 PA1 4,471,972 PA1 4,455,029 PA1 4,506,901 PA1 4,324,414 PA1 1. As an improvement over handrims, it offers